from django import forms
from django.core.exceptions import ValidationError
from crispy_forms.helper import FormHelper
from crispy_forms.layout import Layout, Row, Column, Submit, HTML
from crispy_forms.templatetags.crispy_forms_field import css_class
from .models import InviteSettings


class InviteSettingsForm(forms.ModelForm):
    class Meta:
        model = InviteSettings
        fields = [
            'default_password',
            'enforce_random_password',
            'required_user_level',
            'random_password_length',
            'random_password_complexity',
            'invite_expiration',
            'download_1_label',
            'download_2_label',
            'download_3_label',
            'download_4_label',
            'download_5_label',
            'download_1_url',
            'download_2_url',
            'download_3_url',
            'download_4_url',
            'download_5_url',
            'download_1_enabled',
            'download_2_enabled',
            'download_3_enabled',
            'download_4_enabled',
            'download_5_enabled',
            'download_instructions',
            'invite_url',
            'invite_text_body',
            'invite_email_subject',
            'invite_email_body',
            'invite_email_enabled',
            'invite_whatsapp_body',
            'invite_whatsapp_enabled',
        ]

    def __init__(self, *args, **kwargs):
        super(InviteSettingsForm, self).__init__(*args, **kwargs)

        # Define boolean dropdown choices
        bool_choices = [(True, 'Enabled'), (False, 'Disabled')]
        bool_coerce = lambda x: True if x == 'True' else False

        for field_name in [
            'download_1_enabled',
            'download_2_enabled',
            'download_3_enabled',
            'download_4_enabled',
            'download_5_enabled',
            'enforce_random_password',
        ]:
            self.fields[field_name] = forms.TypedChoiceField(
                choices=bool_choices,
                coerce=bool_coerce,
                widget=forms.Select(),
                required=False,
                initial=self.instance.__dict__.get(field_name, True) if self.instance and self.instance.pk else True,
            )

        self.fields['download_1_url'].label = 'URL'
        self.fields['download_2_url'].label = 'URL'
        self.fields['download_3_url'].label = 'URL'
        self.fields['download_4_url'].label = 'URL'
        self.fields['download_5_url'].label = 'URL'
        self.fields['download_1_label'].label = 'Text'
        self.fields['download_2_label'].label = 'Text'
        self.fields['download_3_label'].label = 'Text'
        self.fields['download_4_label'].label = 'Text'
        self.fields['download_5_label'].label = 'Text'
        self.fields['download_1_enabled'].label = 'Status'
        self.fields['download_2_enabled'].label = 'Status'
        self.fields['download_3_enabled'].label = 'Status'
        self.fields['download_4_enabled'].label = 'Status'
        self.fields['download_5_enabled'].label = 'Status'
        self.fields['download_instructions'].label = 'Web Page Instructions'
        self.fields['invite_email_subject'].label = 'Email Subject'
        self.fields['invite_email_body'].label = 'Email Message'
        self.fields['invite_email_enabled'].label = 'Email Enabled'
        self.fields['invite_whatsapp_body'].label = 'WhatsApp Message'
        self.fields['invite_whatsapp_enabled'].label = 'WhatsApp Enabled'
        self.fields['invite_text_body'].label = 'Text Message'
        self.fields['invite_expiration'].label = 'Expiration (minutes)'
        self.fields['enforce_random_password'].label = 'Random Password'
        self.helper = FormHelper()
        self.helper.form_method = 'post'

        self.helper.layout = Layout(
            Row(
                Column(
                    HTML("<h3>General Settings</h3>"),
                    Row(
                        Column('invite_url', css_class='form-group col-md-12 mb-0'),
                    ),
                    Row(
                        Column('required_user_level', css_class='form-group col-md-6 mb-0'),
                        Column('invite_expiration', css_class='form-group col-md-6 mb-0'),
                    ),
                    HTML('<hr>'),
                    Row(
                        Column(HTML("<h5>User Authentication</h5>"), css_class='form-group col-md-12 mb-0'),
                        Column('enforce_random_password', css_class='form-group col-md-6 mb-0'),
                        Column('default_password', css_class='form-group col-md-6 mb-0'),
                        css_class='form-row'
                    ),
                    Row(
                        Column('random_password_length', css_class='form-group col-md-6 mb-0'),
                        Column('random_password_complexity', css_class='form-group col-md-6 mb-0'),
                        css_class='form-row'
                    ),
                    HTML("<hr>"),
                    Row(
                        Column(HTML("<h5>Download Buttons</h5>"), css_class='form-group col-md-12 mb-0'),
                        Column('download_1_label', css_class='form-group col-md-3 mb-0'),
                        Column('download_1_url', css_class='form-group col-md-6 mb-0'),
                        Column('download_1_enabled', css_class='form-group col-md-3 mb-0'),
                        css_class='form-row'
                    ),
                    Row(
                        Column('download_2_label', css_class='form-group col-md-3 mb-0'),
                        Column('download_2_url', css_class='form-group col-md-6 mb-0'),
                        Column('download_2_enabled', css_class='form-group col-md-3 mb-0'),
                        css_class='form-row'
                    ),
                    Row(
                        Column('download_3_label', css_class='form-group col-md-3 mb-0'),
                        Column('download_3_url', css_class='form-group col-md-6 mb-0'),
                        Column('download_3_enabled', css_class='form-group col-md-3 mb-0'),
                        css_class='form-row'
                    ),
                    Row(
                        Column('download_4_label', css_class='form-group col-md-3 mb-0'),
                        Column('download_4_url', css_class='form-group col-md-6 mb-0'),
                        Column('download_4_enabled', css_class='form-group col-md-3 mb-0'),
                        css_class='form-row'
                    ),
                    Row(
                        Column('download_5_label', css_class='form-group col-md-3 mb-0'),
                        Column('download_5_url', css_class='form-group col-md-6 mb-0'),
                        Column('download_5_enabled', css_class='form-group col-md-3 mb-0'),
                        css_class='form-row'
                    ),
                    Row(
                        Column(
                            Submit('submit', 'Save', css_class='btn btn-success'),
                            HTML(' <a class="btn btn-secondary" href="/vpn_invite/">Back</a> '),
                            css_class='col-md-12'
                        ),
                        css_class='form-row'
                    ),
                    css_class='col-xl-6'),
                Column(
                    HTML("<h3>Message templates</h3>"),
                    Row(
                        Column('download_instructions', css_class='form-group col-md-12 mb-0'),
                        css_class='form-row'
                    ),
                    HTML("<hr>"),
                    Row(
                        Column(HTML("<h5>Email Message Template</h5>"), css_class='form-group col-md-12 mb-0'),
                        Column('invite_email_subject', css_class='form-group col-md-12 mb-0'),
                        Column('invite_email_body', css_class='form-group col-md-12 mb-0'),
                        css_class='form-row'
                    ),
                    Row(
                        Column('invite_email_enabled', css_class='form-group col-md-6 mb-0'),
                        css_class='form-row'
                    ),
                    HTML("<hr>"),
                    Row(
                        Column(HTML("<h5>WhatsApp Message Template</h5>"), css_class='form-group col-md-12 mb-0'),
                        Column('invite_whatsapp_body', css_class='form-group col-md-12 mb-0'),
                        Column('invite_whatsapp_enabled', css_class='form-group col-md-12 mb-0'),
                        css_class='form-row'
                    ),
                    HTML("<hr>"),
                    Row(
                        Column(HTML("<h5>Text Message Template</h5>"), css_class='form-group col-md-12 mb-0'),
                        Column('invite_text_body', css_class='form-group col-md-12 mb-0'),
                        css_class='form-row'
                    ),
                    css_class='col-xl-6'),
                css_class='row'),
        )

    def clean(self):
        cleaned_data = super().clean()

        # Validate invite_url: it must start with 'https://' and end with '/invite/'
        invite_url = cleaned_data.get('invite_url')
        if invite_url:
            if not invite_url.startswith("https://"):
                self.add_error('invite_url', "Invite URL must start with 'https://'.")
            if not invite_url.endswith("/invite/"):
                self.add_error('invite_url', "Invite URL must end with '/invite/'.")

        # Validate invite_expiration: must be between 1 and 1440 minutes
        invite_expiration = cleaned_data.get('invite_expiration')
        if invite_expiration is not None:
            if invite_expiration < 1 or invite_expiration > 1440:
                self.add_error('invite_expiration', "Expiration (minutes) must be between 1 and 1440.")

        # Validate default_password based on enforce_random_password flag
        default_password = cleaned_data.get('default_password', '')
        enforce_random_password = cleaned_data.get('enforce_random_password')
        random_password_length = cleaned_data.get('random_password_length')
        if enforce_random_password is True:
            if default_password:
                self.add_error('default_password',
                               "Default password must not be provided when random password is enabled.")
            if random_password_length < 6:
                self.add_error('random_password_length', "Random password length must be at least 6 characters.")
        else:
            # When random password is disabled, default password must be provided and have at least 6 characters.
            if not default_password:
                self.add_error('default_password',
                               "Default password must be provided when random password is disabled.")
            elif len(default_password) < 6:
                self.add_error('default_password', "Default password must be at least 6 characters long.")

        # Validate download buttons: if enabled, the respective text and url fields must not be blank.
        for i in range(1, 6):
            enabled = cleaned_data.get(f'download_{i}_enabled')
            label = (cleaned_data.get(f'download_{i}_label') or '').strip()
            url = (cleaned_data.get(f'download_{i}_url') or '').strip()
            if enabled:
                if not label:
                    self.add_error(f'download_{i}_label',
                                   "Text field must not be empty when download button is enabled.")
                if not url:
                    self.add_error(f'download_{i}_url', "URL field must not be empty when download button is enabled.")

        # Validate that default_password is not contained in any message templates or the subject
        message_fields = ['invite_text_body', 'invite_email_subject', 'invite_email_body', 'invite_whatsapp_body']
        if default_password:
            for field in message_fields:
                content = cleaned_data.get(field, '')
                if default_password in content:
                    self.add_error('default_password',
                                   f"Default password must not be contained in {field.replace('_', ' ')}.")

        # Validate that all message templates include the placeholder '{invite_url}'
        for field in message_fields:
            if field != 'invite_email_subject':
                content = cleaned_data.get(field, '')
                if '{invite_url}' not in content:
                    self.add_error(field, "The template must include the placeholder '{invite_url}'.")

        return cleaned_data